Conventionally, radio receivers are used for audio stereo reproduction systems such as all-in-one stereo systems and separate stereo components, portable audio systems, car-mounted audio systems. The radio receiver receives and demodulates broadcast signals broadcast from a radio station and allows users to listen to programs and musical compositions.
On the other hand, the radio station publicizes various information about its programs on the Internet home page, and as well as the broadcasting of the programs, provides musical composition information about musical compositions broadcast in the programs such as their titles and artist names, to the audiences as associated information.
There is proposed an audio reproduction apparatus as a client terminal having the radio reception function and the Internet connection function implemented in one system that simultaneously performs listening of radio programs and acquisition of musical composition information (see Patent Document 1, for example).
This audio reproduction apparatus allows a user to listen to a program from the above audio reproduction apparatus and acquire the contents of musical compositions broadcast in the program from the radio station, and acquire musical composition information such as the titles and the artist names related to the above musical compositions from a predetermined associated information provision server.    Patent Document 1—Patent Application No. 2003-274302
The audio reproduction apparatus transmits for example the title or the artist name in the associated information obtained from the associated information provision server to a CD seller server, gets the CD searched based on the title or the artist name by the above CD seller server, and can receive the retrieval result from the CD seller server.
By the way, in the aforementioned audio reproduction apparatus, the association information to be transmitted to the CD seller server is limited to the title and the artist name. The retrieval result by the CD seller server is about CDs having that title and CDs containing the same artist name. The retrieval result has no variety, and there has been a problem that a desired CD cannot be always searched.